A matrix of applications that have been (or are being) built for the laptop can be found here.

OLPC software is a set of carefully chosen and integrated Linux applications, creating an innovative user environment.

Basically, the laptop runs the Fedora 7 Linux distribution; On top of the X Window System and the Matchbox window manager, we run a novel Sugar user interface and support library, supporting a core set of "activities". Activities are programs that follow the OLPC Human Interface Guidelines. There is an emphasis on Python and GTK. Other Linux software can be run too, but having a common and enabling user interface is nice; requiring additional libraries (KDE, java runtime, whatever) is in tension with disk and memory limits.

This text went by on boston-pig, from doug. It should be integrated above.

The project needs help on just about every level.
There are open tickets at http://dev.laptop.org/ for documentation,
translation, python programming, c kernel programming, UI work, and of
course bugs.
There is a special section of bugs for people who are not familiar with the
system but want to help out: